Regions
Northwest Coastal.
Pockets of reactive wind slab remain a concern for wind-exposed alpine and tree line areas.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
Isolated flurries with a mild inversion for the week as temperatures gradually warm up. Snow on Thursday. TUESDAY: Cloudy with some flurries (2-5 cm possible). Ridge wind moderate south west. Temperature -3. Freezing level 500m with an AFL from 1200m to 1700m. WEDNESDAY: Cloudy with isolated flurries. Ridge wind moderate from the south. Temperature -2. Freezing level 500m with an AFL from 1100m to 1900m. THURSDAY: Snow. Accumulation 10-15 cm. Ridge wind strong from the south. Temperature -2. Freezing level 600 m.
Avalanche Summary
No new avalanches observed.
Snowpack Summary
Only about 5cm of new snow fell as we woke up to a new year. Cold temperatures and strong winds (from a wide range of directions) have affected the surface snow over the past week, scouring some slopes down to an old crust and forming hard deposits in many other areas. There are some lingering wind slabs, found on a variety of old surfaces including a thick melt-freeze crust that formed in mid-December. Cornices have also been noted at ridge tops, lee (downwind) to strong north east winds last week. In non-wind affected terrain, 20-40 cm of unconsolidated (aka faceted or 'sugary') snow overlies the mid-December crust layer. This snow has been sluffing in steep terrain.Beneath the mid-December crust the snowpack is reported to be generally strong with the possible exception of areas around Stewart and northern parts of the region where the late-October, basal crust can be found near the base of the snowpack. Weak sugary snow may exist around this basal crust and could be triggered from shallow snowpack areas.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.